artifactory service start fails with zip installation on ubuntu 18.04

$ sudo service artifactory start

Job for artifactory.service failed because the service did not take the steps required by its unit configuration.
See "systemctl status artifactory.service" and "journalctl -xe" for details.

$ tail -10 /var/log/syslog

Jun  9 10:25:09 artifactory systemd[1]: Failed to start Setup Systemd script for Artifactory in Tomcat Servlet Engine.
Jun  9 10:25:14 artifactory systemd[1]: artifactory.service: Service hold-off time over, scheduling restart.
Jun  9 10:25:14 artifactory systemd[1]: artifactory.service: Scheduled restart job, restart counter is at 2.
Jun  9 10:25:14 artifactory systemd[1]: Stopped Setup Systemd script for Artifactory in Tomcat Servlet Engine.
Jun  9 10:25:14 artifactory systemd[1]: Starting Setup Systemd script for Artifactory in Tomcat Servlet Engine...
Jun  9 10:25:14 artifactory artifactoryManage.sh[10797]: /usr/bin/java
Jun  9 10:25:14 artifactory artifactoryManage.sh[10797]: Artifactory Tomcat already started
Jun  9 10:25:14 artifactory systemd[1]: artifactory.service: Can't open PID file /opt/artifactory/run/artifactory.pid (yet?) after start: No such file or directory
Jun  9 10:25:14 artifactory systemd[1]: artifactory.service: Failed with result 'protocol'.
Jun  9 10:25:14 artifactory systemd[1]: Failed to start Setup Systemd script for Artifactory in Tomcat Servlet Engine.

If this issue persists on Artifactory 6.14+ for whatever reason (such as on Ubuntu 18.04.2), can try steps found at http://web.archive.org/web/20181012191636/http://vivin.net/2018/09/26/getting-artifactory-running-on-ubuntu-18-04/